硼砂对磷酸镁水泥抗压强度的影响研究

Effect of Borax on Compressive Strength of Magnesium Phosphate Cement

研究了磷酸二氢钾与重烧氧化镁的质量比（P/M）、水胶比对磷酸镁水泥（MPC）硬化性能的影响,并探讨了硼砂对磷酸镁水泥性能的影响。测试了磷酸镁水泥的抗压强度,并利用XRD和SEM分析了磷酸镁水泥的水化产物的物相组成和微观形貌。结果表明,磷酸镁水泥的抗压强度随P/M质量比的增加先增大后减小,当P/M=1∶3时达到最大值,此时产生的水化产物为结晶度很好的板状晶体;随着水胶比的增大,磷酸镁水泥的抗压强度先增大后减小,当其在0.12~0.14时达到最大值;随着硼砂掺量的增加,磷酸镁水泥各龄期的抗压强度先增大后减小,且随着龄期的增长抗压强度逐渐增大;加入硼砂后,磷酸镁水泥晶体呈现出裂纹和缺陷。

Studied the influences of the mass ratio of potassium dihydrogen phosphate to dead burned magnesia （P/M） and water-cement ratio on magnesium phosphate cement （ MPC ） hardening properties, and borax on MPC properties influence was studied. Tested the compressive strength of MPC, X-ray diffraction （XRD） and scanning electron microscope （SEM）were employed to analysis the phase composition and microstructure of MPC hydration products. Results show that, the compressive strength of MPC changed with P/M first and then decrease, when its value at 1 ： 3 which reached maximum, and MPC hydration products are plate crystals with good crystallinity degree. With the water-cement ratio increasing, MPC compressive strength first and then decrease, and reached maximum between 0. 12 and 0. 14. with the dosage of borax increasing, MPC compressive strength at every curing time first and then decrease, and increase with curing time. When borax added, the crystal of MPC appear cracks and defects.